The present invention relates to systems for monitoring railroad cars. More specifically, it relates to a system for monitoring railroad cars that includes a satellite transmitter.
Railroad hopper cars carrying bulk particulate matter, such as grain or plastic pellets, are typically unloaded by applying a vacuum conveying line to an outlet gate positioned at the bottom of each car compartment. The primary air flow for the vacuum conveying line is obtained from the exterior of the car. However, the rate of content removal results in reduction in pressure above the lading. The top of the car compartment must be vented to compensate for material drawn out the bottom of the compartment. Failure to vent the top of the compartment would reduce the efficiency of the vacuum unloading process and even risk damage to the car structure.
Vented hatch covers are known. They represent a successful solution to the prior deficiencies associated with non-vented hatch covers. Such vented hatch covers are available from Salco Products Inc., Lemont, Ill. These configurations are disclosed in commonly assigned U.S. Pat. Nos. 4,819,830 and 5,064,089 and U.S. patent application Ser. No. 11/610,421, the disclosures of which are incorporated herein by reference. Some of the embodiments of the present invention incorporate a satellite transmission system attached to a vented hatch cover of the type in U.S. Pat. Nos. 4,819,830 and 5,064,089 and U.S. patent application Ser. No. 11/610,421.
Once the hopper cars arrive to their destination, the loaded hopper cars may remain in the railroad yard for several days, or even months, until they are ready to be unloaded. It is typical for the buyer to pay the seller for the cargo only after it has been unloaded from the hopper car. Therefore, when the cargo was unloaded from the hopper car is important to both the seller and the buyer. Since the seller is not involved in the unloading process, the seller would need to rely solely on the buyer to provide him with the date on which the carge was unloaded. Some of the embodiments of the present invention provide the seller with the benefit of receiving a report when the hopper car is being unloaded.
Railroad cars are typically equipped with handbrakes which can be set or engaged when the cars are held in the railroad yard. Occasionally the operator forgets to disengage the handbrake and the railroad car is dragged with the handbrake remain engaged. With the handbrake engaged, the car wheels skid rather than roll. This may cause a flat spot on the wheels and/or ruin the brake shoes. Some of the embodiments of the present invention provide the car owner with the benefit of monitoring the status of the handbrake engagement of the car.
Railroad cars frequently require security mechanisms to preserve the integrity of the contents of the car compartments. Often it is desirable to be aware of instances of unauthorized opening of or entry into such car compartments through the hatch opening. This is particularly true in those situations where theft or contamination of the contents of the compartments is otherwise difficult to ascertain. Such situations exist, for example, where the contents of the car compartment is in bulk or infrequently inventoried, or where even small amounts of certain contaminants are unacceptable. Comprehensive testing for contaminants is usually impractical or prohibitively expensive. Some of the embodiments of the present invention provide the car owner with a security system which monitors the position of the hatch cover and sends a report that the hatch cover has been opened.